TY - JOUR
T1 - Bulk switching instrumentation amplifier for a high-impedance source in neural signal recording
AU - Han, Myungjin
AU - Kim, Boram
AU - Chen, Yi An
AU - Lee, Hyojung
AU - Park, Seung Han
AU - Cheong, Eunji
AU - Hong, Jongill
AU - Han, Gunhee
AU - Chae, Youngcheol
N1 - Publisher Copyright:
© 2014 IEEE.
PY - 2015/2
Y1 - 2015/2
N2 - Flicker noise is the most crucial issue in an instrumentation amplifier (IA) for neural recordings because low-frequency neural signals overlap with the frequency of the amplifier's flicker noise. A Chopping technique, often used to reduce the flicker noise, is not desirable for high-impedance input sources due to the charge injection and clock feedthrough from the MOSFETs of the input chopper to the signal source, resulting in a significant increase in the total input-referred noise. Whereas MOSFETs have less flicker noise at the moment of turning on, and the intrinsic flicker noise can be then reduced by turning on and off the MOSFETs in the IA. This brief proposes a bulk switching IA, which can avoid the input current noise. A prototype IA is implemented in a 65 nm CMOS occupying 0.053 mm2, and it achieves the input-referred noise of 0.74 μVrms (local field potential) for 100 k Ω source impedance, a 3.3 times reduction compared with that of the chopper IAs, while consuming only 3.96 μW from a 1.2 V supply.
AB - Flicker noise is the most crucial issue in an instrumentation amplifier (IA) for neural recordings because low-frequency neural signals overlap with the frequency of the amplifier's flicker noise. A Chopping technique, often used to reduce the flicker noise, is not desirable for high-impedance input sources due to the charge injection and clock feedthrough from the MOSFETs of the input chopper to the signal source, resulting in a significant increase in the total input-referred noise. Whereas MOSFETs have less flicker noise at the moment of turning on, and the intrinsic flicker noise can be then reduced by turning on and off the MOSFETs in the IA. This brief proposes a bulk switching IA, which can avoid the input current noise. A prototype IA is implemented in a 65 nm CMOS occupying 0.053 mm2, and it achieves the input-referred noise of 0.74 μVrms (local field potential) for 100 k Ω source impedance, a 3.3 times reduction compared with that of the chopper IAs, while consuming only 3.96 μW from a 1.2 V supply.
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U2 - 10.1109/TCSII.2014.2368615
DO - 10.1109/TCSII.2014.2368615
M3 - Article
AN - SCOPUS:84923117081
VL - 62
SP - 194
EP - 198
JO - IEEE Transactions on Circuits and Systems II: Express Briefs
JF - IEEE Transactions on Circuits and Systems II: Express Briefs
SN - 1549-7747
IS - 2
M1 - 6949641
ER -